Butterfly closure for plastic container

ABSTRACT

A plastic box includes at least one joint between adjacent panels that is held together by a butterfly element on one panel engaging an opening in the other panel.

FIELD OF THE INVENTION

The present invention relates generally to plastic containers.

BACKGROUND OF THE INVENTION

Plastic boxes are used for a wide variety of applications. By way of non-limiting example, half-slotted plastic containers can be used for transporting vegetables such as asparagus. So-called design style trays can also be used for carrying goods.

Regardless of the type or purpose, a plastic container ordinarily is made from a flat substrate, with the panels of what will become the container being established by appropriately forming fold lines and flap cuts in the substrate. To render the substrate into a three-dimensional container, the substrate is folded along the fold lines, the flap cuts are used as appropriate to overlay one panel on another, and so on.

As recognized herein, there is at least one manufacturing joint between at least two adjoining panels when the substrate is rendered into a container, i.e., there is at least one joint that requires some sort of connecting structure, element, or procedure to hold the joint (and, thus, the container) together. Holding such joints closed, which are examples of discontinuities between adjoining flaps that must be bridged, is the focus of the present invention.

SUMMARY OF THE INVENTION

A plastic container includes one or more male elements each of which is integral to a respective panel of a plastic substrate and each of which protrudes away from an edge of its panel. A male element includes a stalk that has a first end connected to the panel, with the stalk defining sides extending from the edge to a second end of the stalk. Opposed ears are integral to the stalk at the second end of the stalk. The ears protrude away from respective sides of the stalk and are biased to a spread configuration. The ears may be folded about the edges of the stalk to a folded configuration. A respective opening is formed in another panel for each male element. Each opening is configured for receiving the ears of its respective male element therethrough when the male element is in the folded configuration. In contrast, the ears cannot fit through the opening when the male element is in the spread configuration, to thereby hold panels together once the male element is engaged with the opening.

In non-limiting implementations the container may be a half-slotted container, in which the two panels define a junction known as a manufacturing joint between them. The present closure closes the joint. In this embodiment, only a single male element with opening need be used. Or, the container may be, e.g., a design style tray, in which case four male elements and respective openings may be formed on the substrate.

In another aspect, a substrate for a plastic container includes at least first and second panels, with the first panel being formed with at least one opening defining a width and with the second panel being formed with at least one butterfly element biased to a spread configuration. In the spread configuration, the butterfly element defines a width greater than the width of the opening such that the butterfly element does not fit through the opening. As contemplated herein however, the butterfly element can be moved to a folded configuration, wherein the butterfly element defines a width less than the width of the opening such that the butterfly element can fit through the opening.

In still another aspect, a closure for a plastic container having first and second panels includes a U-shaped opening in the first panel and butterfly means formed on the second panel, with the butterfly means being movable to pass through the opening and releasable to remain engaged with the opening for holding the panels together.

The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a substrate that can be rendered into a first non-limiting plastic box known as a “half-slotted container”, with the butterfly element in the spread configuration;

FIG. 2 is a perspective view of the first non-limiting box after being rendered into a container shape, showing the butterfly element in the spread configuration and engaged with a corresponding U-shaped opening to hold the respective panels together, with the particular box shown being a top cover shown in an inverted orientation;

FIG. 3A is a close up perspective view of the butterfly element and opening, showing the butterfly element in the folded configuration about to pass through the U-shaped opening, with other portions of the box omitted for clarity;

FIG. 3B is a close up perspective view of the butterfly element and opening, showing the butterfly element in the spread configuration after passing through the U-shaped opening, with other portions of the box omitted for clarity;

FIG. 4 is a plan view of a substrate that can be rendered into a second non-limiting plastic box known as a “design tray” that is useful as a file box; and

FIG. 5 is a plan view of a substrate that can be rendered into a third non-limiting plastic box known as a “display box”.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially to FIGS. 1-3, a container is shown, generally designated 10, that is rendered from a flat substrate 12 that may have a honeycomb (cardboard-like) construction. The substrate preferably is made (e.g., by extrusion) of a plastic such as polypropylene or polyethylene. While the present invention is broadly directed to closures that are useful for many types of containers, FIGS. 1-3 illustrate a half-slotted container that may be used for carrying wet articles such as vegetable bags.

In accordance with principles known in the art, the substrate 12 is a single piece of plastic that is formed with plural fold lines 14, indicated as dashed lines in the drawings, that demarcate the boundaries between adjacent panels 16. Also, the substrate 12 as shown may be formed with plural cuts 18 between adjacent flaps 20 each of which cuts 18 physically separates its adjacent flaps along the length of the cut. The substrate 12 is folded along the fold lines 14 until adjoining panels are perpendicular to each other, with the fold lines 14 establishing the edge between adjacent panels. Also, the flaps 20 likewise are moved owing to the freedom of movement afforded by the cuts 18 to render the substrate 12 into the container configuration shown in FIGS. 2, 3A, and 3B, wherein a substantially paralellepiped-shaped interior chamber 21 is formed for carrying articles.

Various openings may also be formed in the substrate 12 depending on the particular type of non-limiting container that is to be formed. For instance, in the embodiment shown in FIGS. 1 and 2, generally square display openings 22 may be formed centrally in the second and fourth panels 16 of the substrate 12 shown in FIG. 1, starting from the left-most panel. Also, drainage openings 24, which can be wedge-shaped as shown, may be formed on a panel and adjoining flap, straddling the fold line therebetween, so that when the substrate 12 is rendered into its container configuration drainage is provided in the bottom of the container.

Of importance to the present invention is the fact that the first and fourth panels 16, which of necessity are made separate from each other when making a flat substrate, must be joined together to complete the container configuration. When the substrate 12 is rendered into the container configuration shown in FIG. 2, the first and fourth panels 16 define a junction therebetween that is known as a manufacturing joint, and the joint must be secured to hold the container in its shape. Accordingly, the present closure device has been provided.

As shown in FIGS. 1-3, one of the panels 16 is formed with an opening 26. The opening 26 is generally U-shaped. In the non-limiting embodiment shown, the opening 26 has an elongated base segment 28 terminating in parallel arms 30 that are perpendicular to the base segment 28 and that extend away from opposite ends of the base segment 28 in the same direction as each other. Owing to the U-shape, an island 31 of plastic is established between the arms 30 and is contiguous to the base segment 28 as shown. FIG. 1 shows that the panel 16 in which the opening 26 is formed may include a panel region plus an adjoining flap separated from the panel region proper by a fold line, with the base segment 28 being parallel to and straddling the fold line.

FIGS. 1-3 show that the panel (in the embodiment shown, the fourth or right-most panel 16) to which the panel 16 having the opening 26 (in the embodiment shown, the first or left-most panel 16) is to be secured is formed with a male element 32, also referred to herein as a butterfly element. The male element 32 is integral to its panel 16 and protrudes away from the right-most edge of the panel 16 as shown.

Still cross-referencing FIGS. 1-3, the male element 32 includes a stalk 34 a first end of which is connected to the fourth panel 16. The stalk 34 defines sides 36 that extend from the edge of the panel 16 to the opposite end of the stalk 34. Opposed ears 38 are integral to the stalk 34 and are juxtaposed with the second end of the stalk 34 as shown. The ears 38 protrude away from respective sides 36 of the stalk, and may form semi-circular outer edges 40 as shown.

In accordance with the present invention, the ears 38 are materially biased to the spread configuration shown in FIGS. 1, 2, and 3B. In the spread configuration, the ears 38 extend away from the stalk substantially in opposite directions to each other, substantially coplanar to each other and to the stalk 34, although the skilled artisan will appreciate that due to hysterisis the ears 38 may not resume a completely flat configuration after being folded but may instead angle slightly from the plane of the stalk 34.

As just intimated, the ears 38 manually may be folded substantially about the respective edges 36 of the stalk 34 to the folded configuration shown in FIG. 3A, in which the ears may extend parallel to each other in the same direction and more or less perpendicular to the stalk 34, although when in the folded configuration the ears 38 may be folded a bit less than or a bit more than perpendicular to the stalk 34. In any case, when the male element 32 is in the folded configuration, it is generally U-shaped as shown, and it may now be appreciated that the opening 26 is configured for receiving the ears 38 through it when the male element 32 is in the folded configuration. In contrast, the ears 38 cannot fit through the opening 26 when the male element 32, after insertion through the opening 26, is released to assume the spread configuration, as shown in FIGS. 2 and 3B, which thereby holds the panels together. Stated differently, in the spread configuration the butterfly element defines a width that is greater than the width of the opening such that the butterfly element does not fit through the opening, whereas in the folded configuration the butterfly element defines a width that is less than the width of the opening such that the butterfly element can fit through the opening, after which the butterfly element is released to assume the spread configuration. In this configuration, the island 31 presses the stalk 34 against the side of panel facing the stalk, as best shown in FIG. 3B, to retain the present lock in the configuration shown and, hence, to more securely connect the first and fourth panels together.

FIG. 2 shows that in non-limiting implementations the top of the box (which is shown inverted in FIG. 2) has stack tabs 42 as shown that can interlock with complementary structure on another box, for securely stacking plural boxes. The stack tabs 42 are bent 90 degrees from the substrate surface to assume the orientation shown in FIG. 2. Owing to the fact that the stack tabs 42 are honeycomb plastic like the rest of the preferred box, they are relatively sturdy.

FIG. 1 shows that additional fastening devices may be formed on the substrate 12, including one or more J-locks 44 (or, equivalently, L-locks) that engage respective double-D openings 46.

One and only one butterfly closure may be used in the non-limiting embodiment shown in FIGS. 1-3. However, in other container configurations, such as the design style tray whose substrate 50 prior to rendering into a container is shown in FIG. 4, may include plural butterfly closures, e.g., the substrate 50 is formed with four male elements 52 and four respective openings 54, with a male element-opening pair being formed in the substrate perpendicular to each other. After the substrate is folded into the container configuration for, e.g., holding files, a male element-opening pair are parallel to each other and are juxtaposed with each other for engagement therebetween. To that end, the substrate 50 shown in FIG. 4 may have a top row of first through third panels 56 (from left to right), a middle row of fourth through sixth panels 56, and a bottom row of seventh through ninth panels, with display openings 58 being formed in the first, third, seventh, and ninth panels as shown.

FIG. 5 shows yet another substrate 60 that may be rendered into a display container. The non-limiting substrate 60 has a single row of first through fourth panels 62, with a butterfly element 64 in the fourth panel engaging an opening 66 in the first panel in accordance with principles above to hold the substrate in the container configuration. Each panel may be formed with a display window 68 as shown.

While the particular BUTTERFLY CLOSURE FOR PLASTIC CONTAINER as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more”. It is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. Absent express definitions herein, claim terms are to be given all ordinary and accustomed meanings that are not irreconcilable with the present specification and file history. 

1. A plastic container, comprising: at least one male element integral to at least a first panel of a plastic substrate and protruding away from an edge thereof, the male element including: a stalk having a first end connected to the first panel, the stalk defining sides extending from the edge to a second end; opposed ears integral to the stalk and juxtaposed with the second end of the stalk, the ears protruding away from respective sides of the stalk, the ears being biased to a spread configuration, the ears being foldable substantially about the edges of the stalk to a folded configuration; and at least one opening integral to at least a second panel of the substrate and configured for receiving the ears therethrough when the male element is in the folded configuration, the ears not fitting through the opening when the male element is in the spread configuration.
 2. The container of claim 1, wherein the container is a half-slotted container.
 3. The container of claim 2, wherein the panels define a junction therebetween when the male element is engaged with the opening, the junction being a manufacturing joint.
 4. The container of claim 3, comprising one and only one male element.
 5. The container of claim 1, wherein the container is a design style tray.
 6. The container of claim 6, comprising four male elements and respective openings.
 7. The container of claim 1, wherein the ears extend away from the stalk substantially in opposite directions to each other when in the spread configuration.
 8. A substrate for a container, comprising: at least first and second panels, the first panel being formed with at least one opening defining a width; the second panel being formed with at least one butterfly element biased to a spread configuration, wherein the butterfly element defines a width greater than the width of the opening such that the butterfly element does not fit through the opening, the butterfly element being movable to a folded configuration, wherein the butterfly element defines a width less than the width of the opening such that the butterfly element can fit through the opening.
 9. The substrate of claim 8, wherein the butterfly element comprises: a stalk having a first end connected to the first panel, the stalk defining sides extending from the edge to a second end; and opposed ears integral to the stalk and juxtaposed with the second end of the stalk, the ears protruding away from respective sides of the stalk, the ears being biased to the spread configuration, the ears being foldable substantially about the edges of the stalk to the folded configuration.
 10. The substrate of claim 8, wherein the substrate can be rendered into a half-slotted container.
 11. The substrate of claim 10, wherein the panels define a junction therebetween when the butterfly element is engaged with the opening, the junction being a manufacturing joint.
 12. The substrate of claim 11, comprising one and only one butterfly element.
 13. The substrate of claim 8, wherein the container is a design style tray.
 14. The substrate of claim 13, comprising four butterfly elements and respective openings.
 15. The substrate of claim 9, wherein the ears extend away from the stalk substantially in opposite directions to each other when in the spread configuration.
 16. The container of claim 1, wherein in the folded configuration the male element is generally U-shaped, and the opening is generally U-shaped.
 17. The substrate of claim 8, wherein in the folded configuration the butterfly element is generally U-shaped, and the opening is generally U-shaped.
 18. The substrate of claim 8, wherein the substrate is plastic.
 19. A closure for a plastic container having first and second panels, comprising: at least one U-shaped opening in the first panel; and butterfly means formed on the second panel and movable to pass through the opening and releasable to remain engaged with the opening for holding the panels together. 